23747320021 has 4 divisors (see below), whose sum is σ = 23753075500. Its totient is φ = 23741564544.

The previous prime is 23747320013. The next prime is 23747320049. The reversal of 23747320021 is 12002374732.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15608754225 + 8138565796 = 124935^2 + 90214^2 .

It is a cyclic number.

It is not a de Polignac number, because 23747320021 - 2³ = 23747320013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23747320001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2871546 + ... + 2879803.

It is an arithmetic number, because the mean of its divisors is an integer number (5938268875).

Almost surely, 2^23747320021 is an apocalyptic number.

It is an amenable number.

23747320021 is a deficient number, since it is larger than the sum of its proper divisors (5755479).

23747320021 is an equidigital number, since it uses as much as digits as its factorization.

23747320021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5755478.

The product of its (nonzero) digits is 14112, while the sum is 31.

Adding to 23747320021 its reverse (12002374732), we get a palindrome (35749694753).

The spelling of 23747320021 in words is "twenty-three billion, seven hundred forty-seven million, three hundred twenty thousand, twenty-one".